In the past, players who wanted to play at an online casino often had to download software first. This approach uses up precious memory space on any portable device. Nowadays, a lot of casinos allow players to play through a browser, making the gaming experience more streamlined. (Players who don't necessarily want this barrier-free access to online casinos can combat gambling problems with apps that offer therapy or self-exclusion tools.)
Instant play casinos are now commonplace. The only real downside is that games have to be playable across a wide range of devices and connection speeds. Thus, they might not be as sophisticated as downloaded games. Nevertheless, an online HTML5 casino (the modern successor to an online flash casino) makes most games fast and fun to play.
At an instant casino, players still have to register an account in many cases, but this is also changing.